The object of the project is to relate the visually guided behavior of monkeys to cerebral processes. Investigations will be concerned with the following problem areas: (1) The perceptual and discriminative capacities for the spatial and temporal dimensions of visual stimuli. (2) The influence of sensory interactions upon visual perception. (3) The mechanisms of visuo-oculomotor integration and its relationship to detection of movement. (4) The anatomic description of certain portions of the visual and oculomotor pathways. Behavioral methods will include the determination of psychophysical thresholds of visual function, the performance of complex visual habits involving forms and figure-ground articulations, transposition experiments, and the study of an unlearned response such as nystagmus produced either by successive moving stimuli or by intermittent photic stimulation. The importance of cortical and subcortical structures in visual behavior will be determined with the ablation technique. Anatomic investigations will be mostly concerned with the extrageniculate terminations of retinal fibers and the tracing of corticofugal fibers of the oculomotor system.